Technical Field
Certain embodiments of the invention relate to linear motors.
Description of Related Art
A linear motor is used to convert electrical energy into linear motion. FIG. 1 is a perspective view of a linear motor in the related art. FIG. 2 is a plan view showing the arrangement of field magnets of the linear motor in the related art.
A linear motor 2r as represented in FIG. 1 is furnished with a movable element 10 and a stator 20r. The stator 20r is furnished with a pair of yokes (back yokes) 22a and 22b disposed in opposition with the movable element 10 interposed between them, and pluralities of field magnets 24 provided along the way that the movable element 10 travels (along the x-axis) on respective inside lateral surfaces S1a and S1b of the back yokes 22a and 22b. 
As shown in FIG. 2, the pluralities of field magnets 24 include main pole magnets 24a and interpole magnets 24b. The main pole magnets 24a1, 24a2, 24a3 . . . are bonded in place according to a magnetic pole pitch and such that the N poles and S poles appear in alternation. Interpole magnets 24bi, which have magnetic poles oriented along the magnetic field generated by two adjoining main pole magnets 24ai and 24ai+1, are provided in between the adjoining main pole magnet pairs. (Here, i=1, 2, 3 . . . .) The configuration of such a magnetic circuit is called a Halbach array, employed in various linear motors.